(Go here to learn how to replicate this in Western Yellow: https://www.youtube.com/watch?v=wL5LYPFH4q8)
In Japan, Pokémon Yellow came out before the Game Boy Color. Therefore, it is similar to Pokémon Red/Green and Blue in that it is a Game Boy title enhanced only for the Super Game Boy. Like the previous games, players can set a specific color palette at boot time but Yellow uses its own palette by default as well.
Outside Japan, Pokémon Yellow is enhanced for the Game Boy Color and runs in Game Boy Color mode, with the color palettes being more saturated versions of the Super Game Boy palettes and replacing the palette used by Japanese Yellow (though the localizations might still have it, unused).
This requires the Game Boy Color boot ROM if played on an emulator since Japanese Yellow as well as Red/Green and Blue fall back to the grey palette of the original Game Boy otherwise.